Cha Kyungmi · Yi Kiyoun · Shin Myungsun The lexical literacy environment refers to the ‘language literacy envi- ronment that affects the development of lexical competence’. This study causally revealed the relationship between learners’ lexical competence and lexical literacy environment through SEM analysis. About 2,000 learn- ers(third year) from 24 middle schools across the country were analyzed as a sample. As a result, it was found that ‘vocabulary learning activeness, par- ents’ academic background, enjoyment of reading, attitude toward lexical competence’ had a positive effect on learners’ vocabulary scores, and the more negative the learners perceived the ‘vocabulary teaching and learn- ing situation at school’, the higher the vocabulary score. As a result of the analysis between the male and female groups, the difference between the structural equation path coefficients was mostly not statistically sig- nificant, but the ‘attitude toward lexical competence’ had a much greater effect in the female group.